VOL. XIII.] fHILOSOPHICAL TRANSACTIONS. 67Q 



Arabic figure, which is much the same with this, save what here stands upright, 

 there lies flat; and I find it so constantly in many of the ancient manuscripts, 

 before the use of printing. 



Nor need it move any scruple at all, that part of the number is expressed by 

 the numeral letter M, or the word millesimo, of which M° is but a contrac- 

 tion, while the rest is expressed in numeral figures. For the like often occurs 

 in old manuscripts ; and sometimes even at this day. And it rather favours the 

 simplicity of that age, not very nice in such things, especially among me- 

 chanics, than any design of imposture.* 



On the Eclipses of Jupiter's Satellites for the Year following, l684, with a 

 Catalogue of them, and Informations concerning its Use, By Mr, Flamsteed. 

 N° 154, p. 4D4. 



It has been my custom for years past to make quarterly a small ephemeris of 

 the eclipses of Jupiter's satellites visible with us, that none of them might 

 escape me unobserved when the weather permitted; having by this means ob- 

 tained a good stock of observations of them of my own, besides what I had 

 collected from the works of Gallileo, Hodierna, Borelli, the papers of Mr. 

 Rooke, late professor of Geometry, at Gresham College, and the communica- 

 tions of my friends Mons. Cassini and Mr. Townley, I found myself well fur- 

 nished for the restitution of their motions, which I attempted last summer, 

 and accomplished with such success, that having seen only 2 of the predicted 

 eclipses of the first satellites,^ I find neither of them differ above 2 minutes 

 from my calculations. I have also observed one of the third, not above 3 

 minutes faulty, and another of the second erring but 2; which makes me hope 

 the inequality I suspected in this last, will not be found so great as 1 feared 



♦ This subject is treated at greater length by the doctor in his Algebra, cap. 4>, p. 17 j as also by 

 several other writers; some of them agreeing in Dr. Wallis's opinion, while others oppose it. Thus, 

 among others, we shall find in the Philosophical Transactions, No, 439, An. 1735, a dissertation by 

 Dr. John Ward, against the antiquity of the Arabian numerals, and particularly against the above 

 date on the Helmdon mantle - piece j which he conjectures was intended for 1233, rather than 1133: 

 and in the Archaeologia, vol. 13, is a learned paper, (Art. 10,) by the Rev. Samuel Denne, in which 

 he contends for a much later introduction of those numerals, at least in common use as well as in 

 books of science. But, on the other hand, in the Gent. Mag. an. 1800, vol. 70, a writer, (Mr. 

 R. Churton) has given a fac-simile of the above inscription, as large as the letters themselves, 

 taken from the carving itself by a kind of impression on paper; showing that the fig. 1, for the 

 hundred in Dr. Wallis's number, is the true and exact shape of the character; and that it has no. 

 approach to the form of the 2, as conjectured by Dr. Ward. On the whole, the truth seems to be, 

 that those Indian numerals may have been used so nearly in this country, as above, on some particu- 

 lar occasions, though not brought into common use till a century or two later. 



